1. Field Of The Invention
The present invention relates to methods and arrangements by which a plurality of waste PWR fuel assembly nozzles can be stored, in consolidated form, for ultimate disposal as radioactive waste.
2. Description Of The Prior Art
Fuel assemblies for pressurized water (PWR) type nuclear reactors include opposing top and bottom nozzles disposed on either end of any array of elongated fuel rods and control guide thimbles. After a fuel assembly has been in a nuclear reactor for a period of time, it sometimes becomes necessary to gain access to the control rods, an operation which requires removal of at least the top nozzle. In a fuel assembly reconstitution operation, the removed, original top nozzle becomes waste, and a new top nozzle is installed before the reconstituted fuel assembly is placed back in the reactor. When the fuel rods within the assembly become spent, both the top and bottom nozzles become radioactive waste along with the rest of the fuel assembly. In both cases, the waste nozzles need to be disposed of. Unlike some .components, the heavy metallic structure of such waste nozzles are not subject to significant compaction despite efforts to consolidate such nozzles by crushing their attachments by compression. The disposal problem is exacerbated by the fact that no new nuclear waste sites have been approved in recent years and many of the existing ones have been filled to capacity with radioactive waste. Thus, nuclear powered utility plants do not now have a repository to which their waste nozzles may be shipped for disposal and such will not be available for an indefinite period of time in the future. Consequently, nuclear reactor utility plants have no choice but to store the growing number of waste nozzles on site in an ever decreasing amount of storage space. Thus there is an increasing need to find a way to consolidate such waste nozzles in order to make the most efficient use of the limited amount of on site waste storage space. While successful techniques have been developed for consolidating spent fuel rods and skeletal frames of the fuel assemblies, no effective method or arrangement has heretofore been devised to effectively and efficiently consolidate the top and bottom nozzle of such fuel assemblies.